1. Field of the Invention
The present invention relates to a signal control system for a fan motor and, in particular, to a signal control system for a fan motor which can converts a rotation speed signal to an operation signal and then avoids high cost.
2. Description of Prior Art
With the development of recent electronic industry and functional improvement of electronic components, their operational speeds and the amounts of chips inside increase accordingly. When the above-mentioned chips operate, the heat generated also increases. If this heat source cannot be dissipated immediately, the functions of these electronic components will be significantly affected and the processing speed of these electronic components will be decreased. When the heat generated is continuously accumulated, the electronic components will burn out. Therefore, how to dissipate the heat is one of the most important issues of electronic components and a heat-dissipation fan as a heat-dissipation apparatus is a common way.
It is quite common to use the heat-dissipation fan in various fields such as computers, electronic communication, or server equipment. The ordinary fans used in electronic communication or server equipment are in operate in series or in parallel to effectively improve efficiency of heat dissipation. Moreover, the general signal waveforms used in the general heat-dissipation fans are mainly divided into the sinusoidal square wave and the high-low voltage wave (RD). The sinusoidal square wave (FG) is mainly used to detect the rotation speed status of the fan, which is also called the rotation speed signal (FG). The output of the rotation speed signal is obtained by reading the switching number of the fan magnetic field through the system to calculate the fan rotation speed. The high-low voltage wave is mainly used as an output signal which indicates that the fan is rotating or stops. The output of the high-low voltage wave, also called the operation signal (RD), is obtained by outputing a HI voltage level through the system after the fan stops and the magnetic field switches to further determine if the fan rotates normally. For a general fan system, after the rotation speed signal is inputted into the system, only the rotation speed signal (FG) can be outputted and the operation signal (RD) cannot be outputted. The function of signal output of such a system cannot meet the requirements of the current fan system. If the operation signal is required to be outputted from the system, a microprocessor (MCU) is needed to perform the signal conversion. In this way, the rotation speed signal inputted can be converted into the operation signal. As a result, a higher cost is incurred by the installation of the MCU; a circuit design is performed by combing an MCU and a complicated circuit or a controller, which results in a relatively high cost and a complicated design.
Therefore, how to overcome the above problems and disadvantages of the prior art is the focus which the inventor and the related manufacturers in this industry have been devoting themselves to.